Home In Exile
by Hekate1308
Summary: When Sam Winchester called Sherlock Holmes, the consulting detective knew he had to act. Sherlock/Supernatural crossover, Superlock. Written for a tumblr challenge.


**Author's note: I found out there was a Let's Write Supernatural Challenge on tumblr, and I can't stay away from a prompt. The theme was "Crossover" – I couldn't help but write Superlock. Enjoy. **

Sherlock Holmes moved past the footman without a word. The man knew better than to stop him; Sherlock heard him shuffle off to inform his brother that he was there as he made his way into the Visitor's room.

A few minutes later, he heard his brother's steps.

Mycroft entered the room.

"Sherlock. I didn't expect to see you today".

"I solved the case" Sherlock said quickly, not bothering to pretend that Mycroft didn't keep surveillance on him. "It was the housekeeper".

"Of course".

"I need a plane" Sherlock said matter-of-factly. "I need to go to America".

He didn't surprise Mycroft often. Before he had spent two years hiding, he might have enjoyed the expression on his brother's face.

"America?" the British Government asked calmly.

Sherlock nodded. "Lebanon, Kansas to be exact".

He knew Mycroft wouldn't let him go without an explanation, so he continued. "Sam Winchester called me".

Mycroft didn't say anything. He knew who the Winchesters were, of course. In his position, he had to. Hunters were important – they took care of the things politicians couldn't do anything about, couldn't even know about.

He hadn't known Sherlock knew them, though.

They had met when Sherlock had already been gone for a year and been busy taking down a part of Moriarty's web in Indiana.

He had broken into an office building that controlled most of the country's import on fake pieces of art, only to be confronted by a man with black eyes.

He had stumbled upon enough books on lore to know that demons had black eyes. He had never believed, though. Not until this moment.

With a flick of his hand, the man pinned him against a wall. He would have died if Sam and Dean Winchester hadn't barged in at the same moment, the elder brother dousing the man with water and chanting a Latin exorcism.

Sherlock slid down the wall as the demon was banished; a moment later, Dean splashed holy water in his face as well.

"What are you doing here?"

"Roger Carters" he replied calmly. "He is part of a web of criminals I am chasing".

Dean looked at him.

"They're demons, not criminals". He obviously expected him to argue, but Sherlock simply made the request that he be handed a weapon that worked against them.

They didn't have much time, and Sam handed him a weapon despite Dean's grumbling, telling him that it was loaded with rock salt and would hurt demons.

They took down the whole building. There were twelve demons, as well as several human henchmen to deal with, but between the three of them, they managed. Sherlock didn't know any exorcism, but he could shoot until either Sam or Dean came to recite it or the demon left its host.

"I gotta say, man" Dean said afterwards. "You ain't half bad".

Sherlock handed the gun back to him.

"Sherlock Holmes".

"Sam and Dean Winchester" he said, using his hands to indicate who was who.

Sherlock stayed until it was certain that no one remained to take over the part of the web, then he moved on. Not before learning about hunters, though, and realizing that he was lucky that it had been Sam and Dean Winchester who'd run into the building. In such a fight one wanted the very best.

They exchanged phone numbers before he left. He didn't expect to hear from them – if anything, he thought he would be the one to call because he stumbled upon a case with supernatural evidence – but almost a year after he'd returned, his phone rang. He didn't recognize the number.

"Sherlock Holmes."

At first, no one spoke. He waited for a moment – often respective clients would need some time to talk about what had caused them to call him.

Someone cleared their throat.

"It's Sam Winchester".

"Yes" he replied. He knew that Sam would continue speaking.

"It's Dean". His voice broke at his brother's name, and Sherlock knew something must have happened.

"He's – he's gone".

It took him a few minutes to tell the whole story. Sherlock listened and agreed to come immediately. Without them, he would never have returned home.

He had to get there as soon as possible. And for that, he needed one of Mycroft's planes.

"Brother mine, this is hardly – "

"I am going. You would simply save me time".

He made sure that he said it with enough emphasis that Mycroft would know he wouldn't be argued out of his decision.

His brother looked at him.

After a few moments, he sighed.

"The plane will be ready in half an hour. Do you want to take Doctor Watson with you?"

"No". John couldn't leave. He had his praxis and his family. Sherlock hadn't seen him in the last seven weeks.

Mycroft nodded.

Sherlock left to pack a bag.

Half an hour later, he boarded the plane.

He spent the flight looking out the window, thinking about what Sam had told him and how it fit with things he'd read since he had returned. Once he had known demons existed, he had decided that he might as well know everything there was to know about them – if only to be ready to call a hunter when he noticed something odd during a case.

He had done his research. But it wouldn't help him find Dean Winchester.

According to his brother, he had died and his body was gone. Sam believed that his brother was alive, though. Apparently it had happened before.

But even if Dean had come back to life, it didn't explain his disappearance. Even in the short time he had spent with the brothers, he had seen that they were very fond of one another. Dean wouldn't simply leave and not let Sam know where he was going. Whatever had happened, it must be serious indeed.

He needed data. He couldn't form a theory until he had spoken to Sam and seen the scene from which Dean had disappeared.

He retreated into his mind palace for the rest of the flight.

When they arrived, he left without looking back.

Sam had told him where to find the bunker; he didn't pick up when Sherlock called, but he found it without problems.

After he had knocked several times, Sam opened. He looked thin and pale, and there were dark circles beneath his eyes.

"Sherlock! I didn't expect you so soon".

"My brother occupies a minor position in the British Government" he replied. "He was able to obtain a plane for me".

Sam didn't seem to process what he'd said; he simply nodded and let him in.

"Tell me the facts" Sherlock said coldly.

They spent an hour with Sam trying to explain what had happened. Sherlock was less than impressed with Dean's decision to take the Mark of Cain – but, and he would never admit it, there was something extremely human in his deceiving his brother to save his life. Mycroft would never have done such a thing. Sherlock would never have done such a thing.

For Dean Winchester, family came first.

And now he was missing.

It was difficult to tell if Sam was hoping or dreading he was alive. It seemed to be a mixture of both. The effects of the Mark had been devastating; Dean had killed without remorse, had told Sam that he didn't want to become what it was turning him into.

"Do you think that is what happened?" Most clients preferred it if he didn't say the truth out loud, but Sam had seen enough in his life to appreciate it. He answered honestly.

"I don't know".

"Do you have contacts?"

Sam blinked. "What?"

"Contacts" Sherlock explained patiently. "We have to make people look for your brother. At home, I would use my homeless network".

Sam nodded. "I'll call a few people".

Sherlock could have left – there was nothing for him to do, no clues – but he owed these men his life. He would wait.

In the meantime, he began to read about the Mark of Cain. He had read the Bible once, but had found little to hold his interest; religion mostly interested him when it was the motive for murder.

There was more to Cain's story than he had thought.

There were allusions that he might be alive; that he had been a Knight of Hell; there were legends; there were stories; there was –

There was the possibility that Dean had turned into a demon. Sherlock found an old text, after several days of searching, that told of Cain becoming a demon after his death.

This was perhaps what Sam had meant – Dean not liking what the Mark "was turning him into".

Sherlock showed him the text.

The younger Winchester's face fell.

"I had hoped – " he began, then stopped. Sherlock didn't need him to finish the sentence. Of course he had hoped that his brother hadn't turned into a demon.

"We don't have any proof yet" he reminded him. Sam nodded.

"Crowley – the King of Hell you told me about – would he know?"

"I tried to call him after Dean died. He didn't come".

"Summon him, then".

"He won't tell us anything if he doesn't wish to. And since he didn't come, I'm pretty sure he doesn't".

"We have to find something else" Sherlock said, surveying the documents on the table. They had read all of them in the last few days; no other hunter had known anything, and Sam had thrown himself into research that was a little too unspecified for Sherlock's tastes.

"There are ways to track a demon?"

"Yes" Sam confirmed. "Some demons cause lightning storms. There are other signs, too".

Sherlock nodded.

"If Dean has turned into a demon, we should be able to track him. Cain is described in various apocryphal texts as "Knight of Hell", which certainly means a rather powerful demon."

He could feel Sam's reluctance. To have a theory that his brother was a demon was one thing; to have proof was another.

He could understand him. But they needed proof.

Eventually, Sam agreed.

For the next week, they went over weather reports, headlines, whatever they could find.

They soon found a pattern.

A powerful demon was indeed making his way through the United States. He had been in Las Vegas and Chicago and was currently travelling down the Route 66.

Sherlock saw Sam swallow as he followed the demon's progress on the map.

"Route 66?" he inquired.

"Dean always wanted to travel it" Sam said quietly. "No hunts, no distractions – just him and Baby."

"The car?"

"Yes. The Impala."

The car had disappeared at the same time that Dean had.

They were on the road before dawn, driving to the next destination. They would have to track him if they were too late, but he seemed to stay for a few days at every place, so they should catch up to him.

It took them three days to get there. They took turns driving, and only stopped once during the day to get something to eat and a few hours every night at a motel.

Inevitably, they began to talk. Sam asked about his return, about the cases he had solved since then. He had kept himself informed.

Sherlock told him.

And then, during one of the many hours when they were both awake and it seemed no one else was, he began to talk of other things.

About John who had married and had a child and wouldn't have been interested if Sherlock had called him to tell him about Dean; about Mycroft, with whom he spent more time now, but who he had little to say to; about Greg, who called him in on cases, but other than that barely paid attention to him anymore because he had much to do and a new girlfriend; in fact, he told Sam that he was lonely.

He had never used the word in connection with himself, not until he got back and everything had changed.

In return, Sam told him about Dean. About his death. About Castiel, who wouldn't come. About Bobby, who was dead but who he needed right now.

They were two lonely people driving down the same road.

When they got to their destination, the signs hadn't abated; if anything, they had got stronger.

"Is there a way to pinpoint exactly where the demon is?"

Sam's expression was answer enough.

After a fruitless day, Sam wanted to have a beer at a bar; Sherlock didn't drink – John's stag night had been an exception – but he saw a lonely man and agreed.

They walked into the first bar they found.

He felt Sam stiffen beside him at the same moment his eyes fell on the back of a later jacket whose owner was sitting at the bar.

Dean Winchester was sitting in the bar they had just walked into.

He felt Sam move; knew him to be impatient, wanting to cry out his brother's name; grabbed his arm.

"Slowly" he hissed. "We don't know if it's him".

Sam looked at him, and he saw the incomprehension in his eyes; then he understood and nodded.

They moved towards the bar casually and Sam waved him to the right. He understood. They'd sit down at each side of Dean.

Sam held out two fingers and passed a beer to Sherlock before they sat down. The consulting detective didn't open his. The younger Winchester took a long gulp.

Dean spoke first.

"Hi, Sammy".

Sam stiffened.

"Sherlock, it's been a while."

"It has" he confirmed.

"What do you want?"

Sherlock saw Sam's grip tighten around the bottle. He watched Dean smirk, and knew this wasn't the Winchester he had met before.

"What do I want? Dean – "

"Do I have to spell it out for you?"

Dean flashed them his eyes.

Sherlock had been prepared, and Sam didn't bat an eyelid either. The black eyes disappeared, leaving the green ones Sherlock remembered.

"Figured you wouldn't want to see me."

"Dean, that's not –"

"And I don't really care".

Sam didn't flinch, but Sherlock saw that he would have if he hadn't controlled himself.

"The only reason you're alive right now is because it would be too much trouble to clean everything up" Dean continued.

"So I suggest you get out of here and we don't see each other again. Same goes for you, Sherlock. Don't need a consulting detective around here".

He had long since got used to the derogatory tone with which people described his job. He caught Sam's eye.

They left.

Sam began to tremble as soon as they left the bar.

"The people – we couldn't risk – "

Sherlock knew he was saying it as much for his sake as for Sherlock's.

He nodded.

"I – " Sam cleared his throat. "I will find a way to save him".

He would. And if he didn't, he would at least have tried everything.

"Sherlock, you helped me find him. You don't have to stay. This is dangerous".

And Sherlock knew he could go back. He thought of John, who had a child and rarely listened when he talked anymore; he thought of waiting for another call from Lestrade, another case to come his way; he thought of spending evenings with Mycroft, both of them silent, neither of them ready or willing to repair their relationship.

He looked at Sam and saw a lonely man. Just as lonely as he was.

"We will think of something" he said slowly.

Sam stared at him.

Sherlock walked towards the car. He had more than enough time. He could stay.

**Author's note: I hope you liked it, please review. **


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